Hopefully this can stick to fiscal policy and economic impact and not need to be moved to the Soap Box, but that's how I saw it: Most people I know used their checks to pay down debt or put into savings -- as people often do when they see tougher times ahead and increasing job insecurity, which is the prudent thing to do (but not the intent).
And to the extent people spent their stimulus checks, it stimulated China's manufacturing industry as much as it stimulated the domestic economy. That's why I think that if another "stimulus" package is destined to occur, it shouldn't be in the form of direct payments to indlviduals.
What they need is a stimulus package that creates a job for my wife in the town where we live.
We have five figures worth of "economic stimulus" to put into the local economy in terms of items to buy and home improvement projects we're looking to start, but as long as my paycheck and benefits are a single point of failure for us, we're hoarding cash in this economy.
Seriously, though, I suppose it would have to directly provide jobs.